I have flown ET to South Africa in business class on B787 and B77L some month ago. I wouldn't call it low standards in C. Aircraft were new, the lie-flat seats perfect and also solid onboard service. I liked the Ethiopean wine served. Crew was friendly (but not so experienced of course as say LH or SK FAs who have 20-20 years in the air). I would do it again without hesitation in particular due to the very reasonable fares available. Transfer at ADD is a unique experience; far from the posh and efficient European and Asian airports you are used to, but you will survive (and certainly not "horrendous" IMO)